58 On Recent Improvements in Electric Lighting. 



current machine. The Serrin lamp, which is almost ex- 

 clusively used with the Gramme machine ; the Siemens, in 

 several forms ; the Brush, Wallace-Farmer, and Crompton — 

 all these lamps are not only arranged to bring the carbons 

 together as they are consumed, but are so constructed as 

 to maintain them always at the same distance apart. Where 

 such lamps are used with alternate current machines, and 

 where more than one lamp is in the same circuit, a shunt of 

 very high resistance has been lately introduced in the out- 

 side circuit between the carbons, so arranged with either an 

 electro-magnet or other contrivance as to bring the carbons 

 closer together when the resistance of the electric arc is 

 increased beyond that point for which the shunt has been 

 arranged to work. In this way the length of the arc is 

 maintained much more uniform and steady than by simply 

 trusting to the strength of the current. 



A number of lamps have also been introduced in which a 

 light is maintained by incandescence only, notably the Weder- 

 man, Keynir, Andree, &c, the action of all being of a similar 

 nature, namely, that of a very slender, pencil of carbon, the 

 point of which is always in direct contact with a carbon or 

 copper button. Of Edison's platinum wire, and carbon lamps, 

 very little may be said. I do not think that any one who 

 had any experience in electric lighting placed much con- 

 fidence in his proposed plans ; and we now see that Edison 

 has only done the same as others who had experimented in 

 the same direction many years previously — given it up as 

 being impracticable. 



The Jablochkoff candles, about which we read so much, 

 appear to have been considerably improved during the last 

 few months. The removal of the insulating medium from 

 between the carbon pencils, and the arrangement of the 

 lamps, enabling the new carbons to be placed automatically 

 in circuit as the old ones are consumed, has caused this 

 system of lighting to be introduced in many places with con- 

 siderable success. Wilde's lamp is now similar in principle 

 to the JablochkofT, with the advantage of extra simplicity; 

 and the latest form of this description of lamp is the Jamin. 

 This, according to the inventor, M. Jamin, gives a greater 

 amount of light than any other of similar form ; and on its 

 introduction before a number of leading men in Paris lately 

 was spoken of most favourably. 



Now, as to the application 01 the various systems. Where 

 large open spaces, halls, &c, have to be illuminated, the em- 



